3.9 magnitude earthquake rocks southeastern Colorado

In a bit of a rarity for the Centennial State, Colorado experienced a 3.9 magnitude earthquake Sunday evening. According to the U.S. Geological Survey, the quake was centered nine miles east of Eads or 26 miles north of Lamar in the southeastern part of the state.

No damage was reported but the temblor was felt into western Kansas. Mary Breslin of Eads told the Denver Post she felt the shaking. “I really thought it was an explosion,” Breslin said. “It did not occur to me in the beginning that it was an earthquake.”

Originating at a depth of 6.2 miles, the quake occurred at 6:22pm along what state geologist Vince Matthews told the Associated Press might be part of a previously unmapped extension of the Cheraw Fault. See below for complete technical details on the quake.

There's more to this story on the Denver Weather Examiner's site!For more details on this temblor including maps and a look at Colorado’s earthquake history, view the complete story on Examiner.com.

Following on Tropical Storms Ana and Bill, watch for Claudette

Tropical Storms Ana and Bill formed Saturday.  The National Hurricane Center expects a tropical depression off of the coast of Florida to become Tropical Storm Claudette today.
Tropical Storms Ana and Bill formed Saturday. The National Hurricane Center expects a tropical depression off of the coast of Florida to become Tropical Storm Claudette on Sunday.

Following on the first two named storms of the 2009 Atlantic hurricane season forming Saturday, a third may form off the coast of Florida today. Tropical Storm Ana, the first of the season, formed early Saturday. This was followed by Bill later in the day. Today the National Hurricane Center is forecasting that a tropical depression near Florida will reach tropical storm strength by the end of the day and if so, will be assigned the name Claudette.

Tropical Depression Four is currently 90 miles west-southwest of Tampa, Florida and moving to the north-northwest at 16 mph. With maximum sustained winds of 35 mph, the storm is just below the 39 mph threshold to become a tropical storm.

Strengthening is expected and the NHC predicts the system will become a tropical storm before it hits the coast. In anticipation of this, a tropical storm warning has been issued from the Alabama / Florida border east to the Suwannee River in Florida. Rainfall accumulations from 3 to 5 inches are expected with coastal storm surge of 3 to 5 feet.

For more information:

There's more to this story on the Denver Weather Examiner's site!For complete details on this potential triple threat, read the full story on Examiner.com.

Tropical Storm Ana forms in the Atlantic

Tropical Storm Ana has formed in the Atlantic and become the first named storm in that basin of the 2009 season.
Tropical Storm Ana has formed in the Atlantic and become the first named storm in that basin of the 2009 season.

The 2009 hurricane season began on June 1st but it wasn’t until this week that the Atlantic basin finally started to really show signs of life. Tropical Storm Ana has formed over the eastern Atlantic becoming that ocean basin’s first named storm of the 2009 season. By contrast, the Pacific basin has had nine storms with Hurricane Guillermo currently being the latest.

The National Hurricane Center says that Tropical Storm Ana is currently 1,010 miles east of the Leeward Islands where a Tropical Storm Watch may be issued later today. The storm is moving west at 16 mph with maximum sustained winds of 40 mph. The NHC says that Ana is expected to strengthen and pick up speed over the next 48 hours.

For more information:

There's more to this story on the Denver Weather Examiner's site!For more details, view the complete story on Examiner.com.

A new record low maximum temperature set & snow comes to the mountains

Denver has record setting cool temperatures and snow arrives in the Rocky Mountains.  Image courtesy Victor Lewis.
Denver has record setting cool temperatures and snow arrives in the Rocky Mountains. Image courtesy Victor Lewis.

While some parts of the nation experience record setting heat, on Thursday Denver had the opposite problem. The high temperature as measured at Denver International Airport reached a mere 64 degrees. This was two degrees below the previous record low maximum temperature of 66 degrees for this date set in 1925 and previous years. That is also an amazing 24 degrees below the normal temperature for this time of year!

Here in Thornton, we were even cooler than the official temperature on Thursday as the mercury climbed to a mere 61.3 degrees! 

The unseasonably cold weather has also brought an unusual sight to the Colorado mountains in July – snow! Some northern parts of the Rocky Mountains in the state above 12,000 feet received a couple inches of snow.

Climate change to bring more wildfires to the Rockies

Atmospheric scientists claim the potential for a 50% increase in wildfire activity due to global warming. (AP Photo)
Atmospheric scientists claim the potential for a 50% increase in wildfire activity due to global warming. (AP Photo)

Sounding the warning sirens about the potential repercussions of global warming, Harvard scientists announced their belief that the changing climate will result in a 50% increase in the amount of land burned by wildfires by 2050.  Should the predictions come true, the increased smoke from an increase in fires could have the effect of further accelerating warming.

Atmospheric scientists from Harvard’s School of Engineering and Applied Sciences (SEAS) have generated models that show much of the western half of the United States being at much greater risk from wildfires.  The study, published in the Journal of Geophysical Research, is said to be the first to measure the impact of future wildfires on air quality.

SEAS Senior Research Fellow Jennifer Logan said, “Warmer temperatures can dry out underbrush, leading to a more serious conflagration once a fire is started by lightning or human activity.  Because smoke and other particles from fires adversely affect air quality, an increase in wildfires could have large impacts on human health.”

There's more to this story on the Denver Weather Examiner's site!For all the details on this study and what it means to Colorado and the Rocky Mountain Region, check out the full story on Examiner.com.

Denver storm costs $350 million – Second most in state history

A man surveys damage to a vehicle struck by a fallen tree after last week's storms. The June 20th hail and wind storm has racked up costs of $350 million in insurance claims.  Image courtesy Becki Mullen.
A man surveys damage to a vehicle struck by a fallen tree after last week's storms. The June 20th hail and wind storm has racked up costs of $350 million in insurance claims. Image courtesy Becki Mullen.

Last week’s hail and wind storm that brought destruction to the west Denver suburbs of Wheat Ridge and Arvada caused $350 million in insured damage according to the Rocky Mountain Insurance Information Association (RMIIA).  The end result is a storm that now ranks as the second costliest in state history and adds to an already expensive summer storm season.

The July 20th storm has thus far resulted in 52,400 claims, 19,500 of which were for automobile damage and 32,900 were homeowner claims.  RMIIA says that damage would have been much higher had the storm struck during daylight hours when more people and vehicles were on the road instead of in their homes and garages. 

Massive trees were uprooted, power poles snapped, windows shattered, and automobiles dented beyond repair when the storm brought winds in excess of 60 mph and golf ball sized hail to the area.  Two tornadoes also briefly touched down near Castle Rock and Englewood although they were not responsible for significant damage.  90,000 people lost power during the storm and Xcel Energy deployed more than 200 people into the field to restore electricity. 

There's more to this story on the Denver Weather Examiner's site!For all the details, including amazing images and video of the damage, view the complete story on Examiner.com.

August 2009 climate and weather preview posted

Thorntons August weather preview.
Thornton's August weather preview.

As summer vacations wind down and families prepare to send their kids back to school in August, Colorado weather also starts to settle down. The chances for severe weather decrease markedly during August and by the end of the month daytime temperatures are dropping quite a bit as well.

At the start of the month Denver usually averages around 88 degrees for a high temperature. By the end of August that drops to 82 degrees. Similarly, nighttime lows drop from 60 to 53 from the start to the end of the month. Generally clear skies can be expected between midnight and noon but the afternoon often brings showers and thunderstorms. These storms typically develop over the foothills then bring precipitation to the Denver metro area.

Despite that moisture, the chance for severe weather decreases considerably compared to the first two months of summer. Cooler air near the surface helps to create a stable atmosphere thus keeping thunderstorms from usually becoming too intense. After the middle of August, tornadoes and damaging hail are pretty rare. The slow movement of storms this time of year are more likely to produce potentially heavy rain.

Click here to read the complete preview including a look back at what was a record setting month last year.

Study: Nature responsible for global warming, not man

A new study says he El Niño-Southern Oscillation (ENSO) accounts for the vast majority of temperature variability.
A new study says he El Niño-Southern Oscillation (ENSO) accounts for the vast majority of temperature variability.

A new peer-reviewed study calls into question the so-called ‘consensus’ on the causes of global warming by saying that “Nature, not man, responsible for recent global warming.”  The new study authored by three Australian scientists and published in the Journal of Geophysical Research says that the El Niño-Southern Oscillation (ENSO) accounts for the vast majority of temperature variability.

Authored by Chris de Freitas (University of Auckland in New Zealand), John McLean (Melbourne) and Bob Carter (James Cook University), the new study is sure to cause waves among those debating the causes of global warming.  Completely contrary to the mainstream media’s portrayal of climate change, the study says, “little or none of the late 20th century global warming and cooling can be attributed to human activity.”

Lead author de Freitas said in a press release, “The surge in global temperatures since 1977 can be attributed to a 1976 climate shift in the Pacific Ocean that made warming El Niño conditions more likely than they were over the previous 30 years and cooling La Niña conditions less likely.”

Another chance at storm spotter training in the north area

Do these clouds have the potential to bring a tornado?  Learn more at National Weather Service storm spotter training.
Do these clouds have the potential to bring a tornado? Learn more at National Weather Service storm spotter training.

We have written before about the great opportunity the National Weather Service provides by giving storm spotter training during the start of the severe weather season.  Normally these sessions are held in the spring but in response to the very active severe weather of early June, and the increased interest in severe thunderstorms, the National Weather Service in Boulder has added to additional spotter training session next week. 

  • When:  Saturday, July 11
  • Time: 10:00am
  • Where: Broomfield, CO.
  • Exact location: Rocky Mountain Metropolitan Airport, Terminal Building, 11755 Airport Way (formerly Jefferson County Airport)
  • For more information: robert.glancy@noaa.gov

The storm spotter program is a nationwide program with more than 280,000 trained spotters.  These volunteers report weather hazards to their local National Weather Service office providing vital information when severe strikes.  Data from spotters include severe wind, rain, snow measurements, thunderstorms and hail and of course tornadoes. 

Don’t think tornadoes can hit Thornton?  Click here for a look back at the June 3, 1981 twister that hit the city!

Storm spotters are part of the ranks of citizens who form the Nation’s first line of defense against severe weather. There can be no finer reward than to know that their efforts have given communities the precious gift of time–seconds and minutes that can help save lives.

By completing one of these training classes you can become an official storm spotter.  When severe weather strikes, you can report it by calling a special toll free number or submit your report via the National Weather Service’s website. 

Taking the training though doesn’t obligate you to being a storm spotter.  These are great sessions for anyone wanting to learn more about the severe weather we experience in Colorado, whether you want to be an official spotter or not.  All training is free.  Topics include:

  • Basics of thunderstorm development
  • Fundamentals of storm structure
  • Identifying potential severe weather features
  • Information to report
  • How to report information
  • Basic severe weather safety

To learn more about the program, see here:  http://www.crh.noaa.gov/bou/awebphp/spotter.php

Thornton and Denver close out a wet and cool June

This funnel cloud was seen on Tuesday from the Thornton Civic Center (looking north) on June 10th.  Image courtesy Lisa Wilson, the City of Thornton.
This funnel cloud was seen on Tuesday from the Thornton Civic Center (looking north) on June 10th. Image courtesy Lisa Wilson, the City of Thornton.

June 2009 went down in the history books as one of the more unusual June’s on record.  Residents are all of course well aware of the string of severe storms but the Mile High City also were unusually cool and certainly very wet. 

In terms of precipitation, a whopping 4.86 inches of rain fell at the official measuring site at Denver International Airport during the month – the second wettest June since recordkeeping began here in 1872.  We missed out on breaking the record by only a tenth of an inch as the all-time wettest was back in 1882 when 4.96 inches fell in the rain bucket.  Nevertheless, we easily exceed the normal rainfall total for the month which is 1.56 inches.  In fact, we beat that in one day on June 23rd when 1.64 inches fell at DIA.  Here in Thornton we didn’t measure near as much precipitation having recording 3.44 inches for the month.  This is more in line with what areas closer to the actual metro area recorded than what was recorded at DIA.  See below for details on the controversy about Denver’s climate records. 

Temperature wise, we were very cool as well, never breaking the 90 degree mark during the month.  Two days, the 29th and 30th, came close with 89 degrees being recorded as the high temperatures on those days.  This was the first time since 2003 no 90 degree days were recorded in June.  Before that, you would have to go way back to 1972 to find another June when that happened.  The average temperature for June 2009 was 64.4 degrees, 3.2 degrees below the normal of 67.6.  That may be cool but it was nowhere near the record low average for June which is 60.6 set in 1967.  Thornton was just a touch warmer than the official stats from DIA as we recorded 90.0 degrees on the 29th.  Similarly, Thornton’s average temperature was just a bit cooler at 63.2 degrees. 

Then of course there were the storms.  Tornadoes, funnel clouds and hail will probably be the most memorable events of the month, especially the twister that struck the Southlands Shopping Center in Aurora.  In all, DIA recorded 18 days with thunderstorms – eight more than normal.  15 days had precipitation versus the normal of nine.  All those storms also took a toll on what is normally a sunny month.  On average Denver has 70 percent of possible sunshine during the month.  This year we only recorded sunshine 51 percent of the time. 

All that rain we have received in the last two months, especially in June, helps to make one other statistic a bit more tolerable.  Colorado’s snow season runs from July 1 to June 30 each year and for the 2008 – 2009 snow season, we recorded a meager 38.1 inches of the white stuff.  That is a whopping 29 inches below the normal of 67.1 inches.   Thornton fared a bit better on the snowfall front but not by a lot having recorded 48.5 inches for the season.

There is always a ‘but’… 

As always, we would like to remind everyone that all official Denver weather statistics are now taken out at Denver International Airport.  As we outlined a few months ago, moving the official monitoring station 13 miles away has made quite a difference in Denver’s climate records.  Evidence suggests that temperatures and precipitation as measured at DIA differ greatly from what would have been recorded at the old site at Stapleton or near downtown Denver. 

The National Weather Service has finally acknowledged this and has setup a measuring station at the Denver Museum of Nature and Science (click here to view current conditions from it on the Weather Underground).  However, they maintain that Denver’s official statistics will continue to be recorded at DIA and as a result, Denver’s climate records will forever have an asterisk next to them.  If you compare June’s statistics from this new station to the ‘official’ ones at DIA, you will notice that much of what we discuss above, including the temperature and precipitation, would be much different were the statistics being kept by the new station closer to where people actually live.

Denver climate summary for the month of June 2009 – From the National Weather Service

CLIMATE NORMAL PERIOD 1971 TO 2000
CLIMATE RECORD PERIOD 1872 TO 2009
WEATHER         OBSERVED          NORMAL  DEPART  LAST YEAR'S
                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
                                          NORMAL
................................................................
TEMPERATURE (F)
RECORD
 HIGH             104   06/26/1994
 LOW               30   06/02/1951
HIGHEST            89   06/30       104     -15       95  06/26
                        06/29
LOWEST             41   06/08        30      11       37  06/12
AVG. MAXIMUM     77.7              82.1    -4.4     83.9
AVG. MINIMUM     51.1              53.0    -1.9     50.9
MEAN             64.4              67.6    -3.2     67.4
DAYS MAX >= 90      0               6.3    -6.3       10
DAYS MAX <= 32      0               0.0     0.0        0
DAYS MIN <= 32      0               0.0     0.0        0
DAYS MIN <= 0       0               0.0     0.0        0
PRECIPITATION (INCHES)
RECORD
 MAXIMUM         4.96   1882
 MINIMUM            T   1890
TOTALS           4.86              1.56    3.30     0.73
DAILY AVG.       0.16              0.05    0.11     0.02
DAYS >= .01        15               8.7     6.3        4
DAYS >= .10         9                MM      MM        2
DAYS >= .50         4                MM      MM        1
DAYS >= 1.00        1                MM      MM        0
GREATEST
 24 HR. TOTAL    1.64R  06/23 TO 06/23              0.70     06/04 TO 06/05       

SNOWFALL (INCHES)
RECORDS
 TOTAL            0.4   1919
TOTALS            0.0                T
DEGREE_DAYS
HEATING TOTAL      78                60      18       64
 SINCE 7/1       5616              6128    -512     6056
COOLING TOTAL      68               136     -68      144
 SINCE 1/1         94               161     -67      172
FREEZE DATES
RECORD
 EARLIEST     09/08/1962
 LATEST       06/02/1951
EARLIEST                        10/07
LATEST                          05/05
.................................................................
WIND (MPH)
AVERAGE WIND SPEED              8.4
RESULTANT WIND SPEED/DIRECTION   2/147
HIGHEST WIND SPEED/DIRECTION    53/260    DATE  06/26
HIGHEST GUST SPEED/DIRECTION    68/270    DATE  06/26
SKY COVER
POSSIBLE SUNSHINE (PERCENT)   51
NUMBER OF DAYS FAIR            3
NUMBER OF DAYS PC             22
NUMBER OF DAYS CLOUDY          5
AVERAGE RH (PERCENT)     65
WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM             18     MIXED PRECIP               1
HEAVY RAIN                7     RAIN                      10
LIGHT RAIN               17     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       3
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                      14     FOG W/VIS <= 1/4 MILE      6
HAZE                     10                                           

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.

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